The invention concerns a system for monitoring liquid flow in hydraulic (or other liquid) installations, such as pipelines, hydraulic actuating devices or a combination thereof.
The monitoring system with which the invention is concerned comprises a volume flow sensor having a toothed rotor, similar to that in a toothed rotor motor, wherein movements of the toothed rotor are sensed by no-contact detectors which emit electrical pulses in respect of discrete quantities of liquid displaced and equal to the volume of a tooth of the toothed rotor, and a device by which the pulses are processable with respect to the direction of flow through the volume flow sensor and to the pulse frequency, the output of the device indicating of the current operating conditions of the installation with which the monitoring system is used.